This OSX tool is a simple GUI for the CVS ANNOTATE command. It can be used as a droplet (drag a file on to it's dock icon) or files can be dropped into the main window. You'll need to be logged in to CVS for it to work. Once it has annotated a file, you can also find show the CVS LOG and CVS STATUS of the file by pressing the Info button at the bottom left. You can search the file by entering text in the box at the bottom right. The first instance of the text will be highlighted - press Next to find the next occurence.
I wrote this as a quick way of annotating a file without needing to go into my CVS client. It can also cope with annotating working copies in branches, which CVS fails to do by default.